May have screwed up installing new cam. Need help!

Depends on your timing gear manufacturer and cam manufacturer. Which timing mark are you referring to? I think most timing gears, when installing dot to dot, crank dot at 12 o'clock and cam dot at 6 o'clock puts #6 cylinder at tdc firing. So the distributor rotor should be at #6, Vibration damper mark should be a 0 tdc.
If you installed the gears dot to dot (which is correct, see post #3) that is TDC for #6 cylinder and 180 degrees off for #1 cylinder. Now when you put on the balancer you are off 180 degrees. Typically you would bring up the balancer to #1 and then install the distributer to fire #1 cylinder.
Yes and yes. Pull #1 plug and stick your finger in the hole. You can do this with a compression tester hose as well. Turn the engine over until it blows your finger out. That should be #1 TDC (or close) and your balancer should line up with the timing tab. Check your distributor rotor and it should be lining up with #1. If it is pointing towards #6, Pull it and reinstall it correctly.